Can't access wifi

I screwed my wifi setup today. I was trying to move the Duet to a different network and somehow managed to f$^% things up

At this point, neither the old IP network nor the new network registers the duet as connected based on the "connected devices" lists on either.

No problem said I (HAH, jinxed it right there!), did a bit of digging and added the following lines to my config.g (memory card removed from duet and inserted in computer)

m552 s0 ; take AP out of reset, just in case
m588 s"*"; forget all previous access point info
m589 s"---------" P"-------------" i00.00.00.00 ; set new access point with no network address defined

I have replaced the actual ssid and password with dashes here.
The only thing I am iffy on is specifying the ip address in the very last line - the system is supposed to get the ip number from the network DHCP server.

Well of course nothing happens and the printer doesn't seem to connect to anything and I can't get to the web interface because it's not connected.
Based on the lights on the duet, all seems well. The wifi module blinks once.

I will need to give the M587 a letter salad in order to preserve the case of the letters.

I was under the impression that was only needed for something like ponterface which translates all g-code to upper case? Still using ' to force them lowercase should work regardless of serial or config file methinks. I just seem to recall there is something preventing it from enabling the wifi module until after config.g is done. (maybe M552 S0 takes care of that idk)

Thanks, I will give it a try tomorrow morning.
Interesting about adding dwell times - I would have never thought about that but it makes sense ! I will also try with and without M552 S-1 as I am thinking that S0 should be ok ... but don't know for sure.
If I do grab a usb cable and even plug it in on both ends, then what? Do I load a terminal program ? I am running Linux btw. Never tried that before.

@jens55 what firmware version? There’s a bug in early RRF3 versions that doesn’t save the password. Use latest 3.01 RC4. M552 S-1 turns off Wifi, so you can’t add SSID, needs to be in idle mode S0. Though turning off, then idle mode, before sending SSID and password can help.

I am running RRF 3.01-RC3
When hooking up via USB I get something in the line of "no known network found" so I am assuming I have to go to RC4.
SInce I can't update through DWC, which files do I need to put onto the memory card directly to do the upgrade ?

Edit: I copied Duet2CombinedFirmware.bin over to the memory card but there was no change.

Edit 2: serial port running M587 seems to report no networks found so maybe the upgrade to RC4 did not complete ?

While I normally like a challenge, this is getting hard on my forehead and the drywall from too much bashing my head against the wall.
I still can't see the device in my 'connected devices' list on either network
I have now changed the network to be visible.
There is a tiny bit of good news, the serial connection now gives me:
failed trying to connect to "-----" , wifi module is idle

As I said, I have one non alphanumeric character in the password, a period ..... ?????